The overall goal will be the development of a dietary intervention method that is capable of producing large sustained weight losses and is thus suitable for use in clinical trials related to obesity. A recent study by the investigators showed that a method based on principles of antecedent control, namely the provision of food to participants, was successful in almost doubling weight losses over a 12 month period compared to those attained in a standard behavioral weight control program. These weight losses were associated with substantial improvements in cardiovascular risk factors. The purpose of the present proposal is to better understand the factors responsible for the positive effects of this intervention and to extend the principles of antecedent control to the area of maintenance. Study 1 will determine whether there are long-term benefits to food provision by reexamining the 202 participants in the original study one year after the end of treatment. Study 2 will investigate the factors related to the successful food provision intervention by comparing the additive effects of standard behavioral treatment and the three central components of food provision: structured meal plans, prepackaged food and subsidy of the food. It will also explore theoretical mechanisms which may underlie the food provision effect, specifically decision making and stimulus control. Study 3 will evaluate the effectiveness of extend the food provision methodology to families. Overweight spouse pairs will be randomized to treatments in which either one member of the pair participates in treatment and receives food, or both members of the pair participate and are provided with food. Study 4 will determine whether the principles of antecedent control can also be applied to exercise. Participants will be randomized to weight control programs which include either the usual exercise instructions or structured plans for exercise and free passes to exercise facilities near their home. It is hypothesized that providing food for the obese spouse as well as the patient, and providing antecedent control for exercise through structured plans and free passes will both improve the maintenance of weight loss. The proposed studies will provide important data on the effect of these interventions on eating behavior, activity, and body weight, and hopefully result in a more successful long-term weight loss intervention.